Extraction of parametric circuit models from scattering parameters of passive RF components (original) (raw)

Modeling of integrated RF passive devices

IEEE Custom Integrated Circuits Conference 2010, 2010

We describe the use of an electromagnetic (EM) simulator for modeling integrated RF components and circuits. Modern EM simulators are fast and accurate enough to provide good models of such components. An important aspect of advanced IC processes is that the physical properties of wires (width, thickness, and resistance) vary depending on the surrounding wiring. We discuss how the EMX simulator [1] handles widthand spacing-dependent properties in the process description. Because the simulator handles mask-ready layout without the need for manual simplification, it is feasible to simulate thousands of possible designs and build scalable component models. Such scalable models allow fast choices of optimal components that meet user-supplied specifications.

Rational Modeling Algorithm for Passive Microwave Structures and Systems

2012

An efficient identification method is proposed for passive rational approximation of frequency domain responses. The method is applied to compute a transfer function from tabulated S-parameter data of a multiport microwave filter. Numerical results validate the robustness and efficacy of the modeling approach.

Parametric Models Based on the Adjoint Field Technique for RF Passive Integrated Components

IEEE Transactions on Magnetics, 2008

Taking into consideration the variability specific to the nowadays nanotechnologies, the fast extraction of parametric models is a must for the present VLSI and radio-frequency (RF)-integrated-circuit (IC) design environments. The major contribution of the paper is a new, effective methodology for the extraction of parametric compact models for passive RF integrated components with field effects, valid for high-frequency broad range. The proposed numeric method is systematically based on a dual approach, which provides two complementary approximations of the exact solution. Duality is applied both to the spaces where the discrete solution is found as well as to the open boundary conditions. The adjoint field technique is applied in an original manner to the finite-integral techniques to handle the parameter variability of the extracted model. The new method needs much less computing resources for modeling than other numerical methods.

Automatic generation of RF compact models from device simulation

2002

We review a recently proposed methodology for automatic generation of equivalent circuits from physical device simulation. The method is based on the calibration on a simplified equivalent-circuit model on simulation results, and can achieve an optimum balance of model complexity, accuracy, and generality. We discuss some of the possible applications of the technique to the modeling of active devices, parasitic elements, and complex physical effects such as selfheating and hot-carrier transport.

RF COMPONENTS MODELING AND ANALYSIS

RF Passive components are used in the design of RF blocks as well as in system level integration. The efficient and accurate analysis of these components is required in order to meet the RF block or system level performances. I had studied the modeling of RF passive components for fast analysis approaches I had studied and developed a prototype design to simulate RF circuits in Pspice. The aim was to develop a functionality to simulate a RF block in spice simulator. Following issues were considered in this simulation i. S-parameter file compatibility with spice simulator ii. Synthesis and analysis of matching circuits iii. Modeling of passive components S-parameter file compatibility with spice simulator: For the circuit design I had considered system level LNA block and made it compatible with spice format The S-parameter file for LNA was not directly compatible with the spice format. An approach was investigated and a translator was developed to make it spice compatible. Hence a generalized code for Nport S-parameter file conversion to spice format was developed.

Extraction of Passive Device Model Parameters Using Genetic Algorithms

ETRI Journal, 2000

The extraction of model parameters for embedded passive components is crucial for designing and characterizing the performance of multichip module (MCM) substrates. In this paper, a method for optimizing the extraction of these parameters using genetic algorithms is presented. The results of this method are compared with optimization using the Levenberg-Marquardt (LM) algorithm used in the HSPICE circuit modeling tool. A set of integrated resistor structures are fabricated, and their scattering parameters are measured for a range of frequencies from 45 MHz to 5 GHz. Optimal equivalent circuit models for these structures are derived from the s-parameter measurements using each algorithm. Predicted s-parameters for the optimized equivalent circuit are then obtained from HSPICE. The difference between the measured and predicted s-parameters in the frequency range of interest is used as a measure of the accuracy of the two optimization algorithms. It is determined that the LM method is extremely dependent upon the initial starting point of the parameter search and is thus prone to become trapped in local minima. This drawback is alleviated and the accuracy of the parameter values obtained is improved using genetic algorithms.

Macromodeling for RF passives via circuit reduction of VPEC model

Digest of Papers. 2004 Topical Meeting onSilicon Monolithic Integrated Circuits in RF Systems, 2004.

To accelerate the macro-model generation for RF passive components considering parasitics, we introduce the Vector Potential Equivalent Circuit (VPEC) to efficiently model the massively coupled passives, like transmission lines and inductors. It enables the passive sparsification of the inductance matrix by pruning the small off-diagonal elements with the desired accuracy. To further reduce the model order, we apply a hierarchical s-domain circuit reduction to generate a reduced driving-point impedance function, and then use the Brune's one-port network synthesis to realize the impedance function by a low-order RLCM ladder circuit as the compact macro-model. We have applied this method to generate the macro-model for the spiral inductor during the design of a cross-coupled LC oscillator. The synthesized lower-order macro-model is accurate up to 10GHz with 50X speedup in the time-domain simulation.

Network oriented modeling of passive microwave structures

Network oriented modeling of the passive microwave circuits provides a useful representation of the circuit and leads to the reduction of the required computer time and memory capacity. The proposed stability criterion allows dividing the simulation or measurement results into two parts representing a lumped elements model and distributed parameters model. The system identification procedure defines the order of the lumped elements model and the positions of poles and zeros in the complex frequency plane. The time-domain simulation results for the input impedance of the bowtie antenna in comparison with a method of moments solution are presented.